Principles of Agronomy and Crop Production
Principles of Agronomy and Crop Production
This domain tests how crops are established and managed as populations: tillage, seed rate, planting geometry, water and nutrient scheduling, cropping systems and growth analysis. BSEB questions often ask you to convert a recommendation into a field operation or interpret a growth index.
Core rules
- Kharif, rabi and zayed are seasonal categories; cropping intensity = (gross cropped area / net sown area) x 100.
- Intercropping grows two or more crops simultaneously in separate rows; mixed cropping does not use a definite row arrangement; relay cropping overlaps only part of the season.
- LAI is leaf area per unit ground area (m2/m2); CGR is dry matter gain per unit ground area per day (g/m2/day); NAR is per unit leaf area; harvest index = economic yield / biological yield.
- Plant population = 10,000 / (row spacing in m x plant spacing in m) per hectare.
Worked example
Target maize population: rows 60 cm, plants 20 cm. Area per plant = 0.60 x 0.20 = 0.12 m2. Population = 10,000/0.12 = 83,333 plants/ha. With 90% germination and 95% field establishment, seed required = 83,333/(0.90 x 0.95) = 97,467 seeds/ha. At 250 g per 1,000 grains, seed = 97,467 x 250/1,000 = 24,367 g = 24.4 kg/ha. The reasoning matters: adjust upward for both germination and field losses, not downward.
Traps
Do not report plant population per m2 when the question asks per hectare. Keep CGR units; confusing CGR with NAR loses marks. Gross plot and net plot differ because border rows are excluded. Intercropping is not the same as mixed cropping, and cropping intensity can exceed 100%.